Is there a Link between the Presumed Site of Ventricular Arrhythmia Origin and the Underlying Mutation in Patients with Arrhythmogenic Cardiomyopathy?
2Sackler School of Medicine, Tel Aviv University, Israel
3Jesselson Integrated Heart Center, Shaare Zedek Medical Center, Israel
4Institut de Cardiologie, Sorbonne Université, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, France
5Department of Anesthesiology, Sheba Medical Center, Israel
6Heart Institute, Hadassah University Hospital, Israel
Background. Ventricular tachycardia (VT) with a right bundle branch block (RBBB) morphology is rarely observed in patients with arrhythmogenic cardiomyopathy (ACM). Mutations in desmosomal and PLN genes have been identified in most patients with left-dominant and biventricular forms of ACM. It is unknown whether a link exists between the site of VT origin and the mutations involved.
Objective. To correlate genetic results with the presumed site of origin of the RBBB-VT in ACM patients.
Methods. From a European survey (26 centers, 11 countries), 72 ACM patients fulfilling the 2010 Task Force criteria were found to display >1 episode of sustained monomorphic RBBB-VT defined according to QRS pattern in V1. Using a QRS axis–based algorithm to identify the origin of LV scar-related VT (Andreu et al., Heart Rhythm 2018), RBBB-VT was classified as originating from any of the following 4 sites: inferior, lateral, anterior and septal walls. Only pathogenic or likely pathogenic variants were analyzed.
Results. Of the 72 RBBB-VT cases, analysis of QRS axis enabling accurate VT location was possible in 71 patients. Assessment of desmosomal and PLN mutations was carried out in 29 (40.8%) patients who comprised the study group.
The LV segments from which VT presumably originated were the inferior wall (55.2%), the lateral wall (24.1%) and the anterior wall (20.7%). No VT originated from the LV septum.
DSP, PKP2 and PLN mutations were found in 11 (37.9%), 8 (27.6%) and 5 (17.2%) patients, respectively; other desmosomal mutations were involved in 5 (17.2%) patients.
DSP, PKP2 and PLN mutations were most frequently observed when the presumed sites of VT origin were the inferior wall (43.7%), the lateral wall (42.9%) and the anterior wall (50%), respectively.
Conclusions. Our results suggest a possible correlation between the site of origin of VT and genetic results in ACM patients with RBBB-VT. These results require confirmation in greater patient cohorts.
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